Last year we announced our intent to end support for the experimental protocol SPDY in favor of the standardized version, HTTP/2. HTTP/2 is the next-generation protocol for transferring information on the web, improving upon HTTP/1.1 with more features leading to better performance. Since then we've seen huge adoption of HTTP/2 from both webservers and browsers, with most now supporting HTTP/2. Over 25% of resources in Chrome are currently served over HTTP/2, compared to less than 5% over SPDY. Based on such strong adoption, starting on May 15th — the anniversary of the HTTP/2 RFC — Chrome will no longer support SPDY. Servers that do not support HTTP/2 by that time will serve Chrome requests over HTTP/1.1, providing the exact same features to users without the enhanced performance of HTTP/2.

At the same time, Chrome will stop supporting the TLS protocol extension NPN, which allows servers to negotiate SPDY and HTTP/2 connections with clients. NPN has been superseded by the TLS extension ALPN, published by the IETF in 2014. ALPN is already used 99% of the time to negotiate HTTP/2 with Chrome, and the remaining servers can gain ALPN support by upgrading their SSL library.

We are looking forward to HTTP/2 continuing to gain adoption, bringing us an even faster web.

Update: To better align with Chrome's release cycle, SPDY and NPN support will be removed with the release of Chrome 51.

The Physical Web helps users discover URLs relevant to their surroundings via Eddystone bluetooth low-energy beacons. Last year, Chrome for iOS took an initial step in supporting the Physical Web, and the community has already begun exploring promising applications. Starting in version 49, Chrome for Android will also surface Physical Web content, making these experiences available to an even larger audience.

As Physical Web-enabled beacons are becoming more widespread, developers are experimenting with the platform in various ways. One Physical Web demo posted by a Mozilla community contributor shows users how to use bluetooth beacons to discover and interact with a drone. Brookwood Middle School uses beacons from BKON to circulate class notes, sports accomplishments, and news updates. Radius Networks, a beacon manufacturer, recently deployed 1,500 beacons to help attendees of CES® (Consumer Electronics Show) navigate showrooms. The Golden State Warriors utilize the Physical Web with the help of Signal360 to provide fans with highlight videos and welcome content at Oracle Arena.

Physical Web bluetooth beacons enabled a scavenger hunt at CES® 2016.

Now, Physical Web developers can reach Chrome for Android users as well, starting with the Beta channel and rolling out more widely soon. When these users walk by a beacon for the first time, they’ll receive a notification allowing them to enable the Physical Web. On future encounters with beacons, users can quickly see a list of nearby URLs by tapping on a non-vibrating notification waiting for them.

Physical Web experience on Chrome for Android

Developers can make their web content discoverable on the Physical Web by configuring an Eddystone-supported beacon to broadcast a URL of their choice with the Eddystone-URL frame type. Now that the Physical Web is tightly integrated into Chrome for Android, a single deployment can deliver contextual information to Chrome users across multiple mobile platforms.

As we continue to improve the Physical Web experience, we’re excited to see what types of contextual experiences developers build. We encourage anyone to join the conversation on our mailing list and visit the Physical Web cookbook to learn more about what’s possible.

Modern websites often have CSS files with repeated values, such as a few colors reused throughout the page in a color scheme. Altering this data can be tedious and error-prone, since it’s scattered throughout one or more CSS files. To improve this, Chrome now supports CSS custom properties, allowing developers to define property variables in CSS without using external frameworks. Developers can then use thevar() function to reference these custom properties anywhere in the document.

Changing a custom property can update multiple components in a website

CSS custom properties also inherit across shadow roots, so a web component can provide a “style API” that makes it possible to tweak and theme the component without knowing about its internals. The Polymer library uses this platform feature to simplify customizing components.

Background sync with service workers

Previously, sites could lose local changes or become out of sync if a user didn’t stay on the site until updates could be sent over the network. For example, an email client might lose a pending message if the user hit "send" and quickly navigated away. The new Background Sync API improves networking reliability by allowing service workers to schedule a one-off sync of a user’s local changes when the device next connects to the network, even if the site isn’t open.

The <keygen> element is used to generate a key-pair as part of an HTML form. While this can be used to enhance user security, <keygen> and user certificates sent with the MIME type of application/x-x509-user-cert can be exploited to disrupt a user’s secure communication, interfere with the functioning of their devices, or track the user without consent. Going forward, <keygen> will return an empty string by default and user certificates sent with the MIME type of application/x-x509-user-cert will no longer be automatically downloaded and installed.